建筑環(huán)境與設(shè)備工程(暖通)畢業(yè)設(shè)計(jì)外文翻譯

1、南京工程學(xué)院Nanjing Institute Of Technology畢業(yè)設(shè)計(jì)英文資料翻譯The Translation Of The English Material Of Graduation Design學(xué)生姓名:學(xué) 號(hào) :000000000Name： Number： 000000000班 級(jí):K暖通091 Class： KNuantong 091所在學(xué)院: 康尼學(xué)院 College: Kangni College 專 業(yè): 建筑環(huán)境與設(shè)備工程 Profession： Building Environmentand Equipment Engineering指導(dǎo)教師:Tutor： 2

2、013年02月25日英文:Thermal comfort in the future - Excellence and expectationP。 Ole Fanger and Jørn ToftumInternational Centre for Indoor Environment and EnergyTechnical University of DenmarkAbstractThis paper predicts some trends foreseen in the new century as regards the indoor environment and ther

3、mal comfort. One trend discussed is the search for excellence， upgrading present standards that aim merely at an “acceptable" condition with a substantial number of dissatisfied. An important element in this connection is individual thermal control。 A second trend is to acknowledge that elevate

4、d air temperature and humidity have a strong negative impact on perceived air quality and ventilation requirements. Future thermal comfort and IAQ standards should include these relationships as a basis for design。 The PMV model has been validated in the field in buildings with HVAC systems that wer

5、e situated in cold， temperate and warm climates and were studied during both summer and winter。 In nonairconditioned buildings in warm climates occupants may sense the warmth as being less severe than the PMV predicts， due to low expectations。 An extension of the PMV model that includes an expectanc

6、y factor is proposed for use in nonair-conditioned buildings in warm climates。 The extended PMV model agrees well with field studies in nonair-conditioned buildings of three continents.Keywords： PMV， Thermal sensation， Individual control， Air quality， AdaptationA Search for ExcellencePresent thermal

7、 comfort standards (CEN ISO 7730， ASHRAE 55） acknowledge that there are considerable individual differences between peoples thermal sensation and their discomfort caused by local effects， i。e。 by air movement。 In a collective indoor climate， the standards prescribe a compromise that allows for a sig

8、nificant number of people feeling too warm or too cool。 They also allow for air velocities that will be felt as a draught by a substantial percentage of the occupants.In the future this will in many cases be considered as insufficient. There will be a demand for systems that allow all persons in a s

9、pace to feel comfortable。 The obvious way to achieve this is to move from the collective climate to the individually controlled local climate. In offices， individual thermal control of each workplace will be common. The system should allow for individual control of the general thermal sensation with

10、out causing any draught or other local discomfort.A search for excellence involves providing all persons in a space with the means to feel thermally comfortable without compromise.Thermal Comfort and IAQPresent standards treat thermal comfort and indoor air quality separately， indicating that they a

11、re independent of each other。 Recent research documents that this is not true . The air temperature and humidity combined in the enthalpy have a strong impact on perceived air quality， and perceived air quality determines the required ventilation in ventilation standards.Research has shown that dry

12、and cool air is perceived as being fresh and pleasant while the same composition of air at an elevated temperature and humidity is perceived as stale and stuffy。 During inhalation it is the convective and evaporative cooling of the mucous membrane in the nose that is essential for the fresh and plea

13、sant sensation。 Warm and humid air is perceived as being stale and stuffy due to the lack of nasal cooling。 This may be interpreted as a local warm discomfort in the nasal cavity. The PMV model is the basis for existing thermal comfort standards。 It is quite flexible and allows for the determination

14、 of a wide range of air temperatures and humidities that result in thermal neutrality for the body as a whole。 But the inhaled air would be perceived as being very different within this wide range of air temperatures and humidities。 An example： light clothing and an elevated air velocity or cooled c

15、eiling， an air temperature of 28ºC and a relative humidity of 60 may give PMV=0, but the air quality would be perceived as stale and stuffy. A simultaneous request for high perceived air quality would require an air temperature of 2022ºC and a modest air humidity。 Moderate air temperature

16、and humidity decrease also SBS symptoms and the ventilation requirement， thus saving energy during the heating season。 And even with air-conditioning it may be beneficial and save energy during the cooling season。PMV model and the adaptive modelThe PMV model is based on extensive American and Europe

17、an experiments involving over a thousandsubjects exposed to well-controlled environments。 The studies showed that the thermal sensation is closely related to the thermal load on the effector mechanisms of the human thermoregulatory system. The PMV model predicts the thermal sensation as a function o

18、f activity， clothing and the four classical thermal environmental parameters. The advantage of this is that it is a flexible tool that includes all the major variables influencing thermal sensation。 It quantifies the absolute and relative impact of these six factors and can therefore be used in indo

19、or environments with widely differing HVAC systems as well as for different activities and different clothing habits。 The PMV model has been validated in climate chamber studies in Asia as well as in the field， most recently in ASHRAE's worldwide research in buildings with HVAC systems that were

20、 situated in cold， temperate and warm climates and were studied during both summer and winter。 The PMV is developed for steadystate conditions but it has been shown to apply with good approximation at the relatively slow fluctuations of the environmental parameters typically occurring indoors. Immed

21、iately after an upward stepwise change of temperature, the PMV model predicts well the thermal sensation， while it takes around 20 min at temperature downsteps 。Field studies in warm climates in buildings without airconditioning have shown， however， that the PMV model predicts a warmer thermal sensa

22、tion than the occupants actually feel。 For such non-airconditioned buildings an adaptive model has been proposed. This model is a regression equation that relates the neutral temperature indoors to the monthly average temperature outdoors。 The only variable is thus the average outdoor temperature， w

23、hich at its highest may have an indirect impact on the human heat balance. An obvious weakness of the adaptive model is that it does not include human clothing or activity or the four classical thermal parameters that have a wellknown impact on the human heat balance and therefore on the thermal sen

24、sation。 Although the adaptive model predicts the thermal sensation quite well for nonairconditioned buildings of the 1900s located in warm parts of the world, the question remains as to how well it would suit buildings of new types in the future where the occupants have a different clothing behaviou

25、r and a different activity pattern.Why then does the PMV model seem to overestimate the sensation of warmth in nonair-conditioned buildings in warm climates? There is general agreement that physiological acclimatization does not play a role。 One suggested explanation is that openable windows in natu

26、rally ventilated buildings should provide a higher level of personal control than in airconditioned buildings. We do not believe that this is true in warm climates。 Although an openable window sometimes may provide some control of air temperature and air movement， this applies only to the persons wh

27、o work close to a window. What happens to persons in the office who work far away from the window？ We believe that in warm climates airconditioning with proper thermostatic control in each space provides a better perceived control than openable windows.Another factor suggested as an explanation to t

28、he difference is the expectations of the occupants。 We think this is the right factor to explain why the PMV overestimates the thermal sensation of occupants in nonairconditioned buildings in warm climates. These occupants are typically people who have been living in warm environments indoors and ou

29、tdoors， maybe even through generations. They may believe that it is their “destiny” to live in environments where they feel warmer than neutral。 This may be expressed by an expectancy factor, e。 The factor e may vary between 1 and 0。5。 It is 1 for air-conditioned buildings. For non-airconditioned bu

30、ildings， the expectancy factor is assumed to depend on the duration of the warm weather over the year and whether such buildings can be compared with many others in the region that are airconditioned. If the weather is warm all year or most of the year and there are no or few other airconditioned bu

31、ildings， e may be 0.5， while it may be 0.7 if there are many other buildings with airconditioning。 For non-airconditioned buildings in regions where the weather is warm only during the summer and no or few buildings have airconditioning， the expectancy factor may be 0.7 to 0.8， while it may be 0。8 t

32、o 0。9 where there are many airconditioned buildings。 In regions with only brief periods of warm weather during the summer， the expectancy factor may be 0。9 to 1. Table 1 proposes a first rough estimation of ranges for the expectancy factor corresponding to high, moderate and low degrees of expectati

33、on。ExpectationClassification of buildingsExpectancyfactor, eHighNonairconditioned buildings located in regionswhere airconditioned buildings are common.Warm periods occurring briefly during thesummer season。0。9 1。0ModerateNonair-conditioned buildings located in regionswith some airconditioned buildi

34、ngs. Warmsummer season.0。7 0.9LowNonair-conditioned buildings located in regionswith few airconditioned buildings。 Warm weatherduring all seasons。0。5 0。7Table 1。 Expectancy factors for nonair-conditioned buildings in warm climates.A second factor that contributes to the difference between the PMV an

35、d actual thermal sensation in nonairconditioned buildings is the estimated activity。 In many field studies in offices, the metabolic rate is estimated on the basis of a questionnaire identifying the percentage of time the person was sedentary， standing， or walking. This mechanistic approach does not

36、 acknowledge the fact that people， when feeling warm, unconsciously tend to slow down their activity。 They adapt to the warm environment by decreasing their metabolic rate。 The lower pace in warm environments should be acknowledged by inserting a reduced metabolic rate when calculating the PMV.To ex

37、amine these hypotheses further, data were downloaded from the database of thermal comfort field experiments. Only quality class II data obtained in nonairconditioned buildings during the summer period in warm climates were used in the analysis。 Data from four cities （Bangkok, Brisbane， Athens， and S

38、ingapore) were included， representing a total of more than 3200 sets of observations 。 The data from these four cities with warm climates were also used for the development of the adaptive model.For each set of observations， recorded metabolic rates were reduced by 6。7 for every scale unit of PMV ab

39、ove neutral， i。e。 a PMV of 1.5 corresponded to a reduction in the metabolic rate of 10。 Next， the PMV was recalculated with reduced metabolic rates using ASHRAEs thermal comfort tool . The resulting PMV values were then adjusted for expectation by multiplication with expectancy factors estimated to

40、be 0。9 for Brisbane， 0.7 for Athens and Singapore and 0.6 for Bangkok。 As an average for each building included in the field studies, Figure 1 and Table 2 compare the observed thermal sensation with predictions using the new extended PMV model for warm climates.Comparison of observed mean thermal se

41、nsation with predictions made using the new extension of the PMV model for nonair-conditioned buildings in warm climates。 The lines are based on linear regression analysis weighted according to the number of responses obtained in each building。CityExpectancyfactorPMV adjusted toproper activityPMV ad

42、justedfor expectationObservedmean voteBangkok0。62。01.21。3Singapore0.71.20。80。7Athens0。71.00。70。7Brisbane0。90。90。80。8Table 2. Nonair-conditioned buildings in warm climates.Comparison of observed thermal sensation votes and predictions made using the new extension of the PMV model。The new extension of

43、 the PMV model for non-airconditioned buildings in warm climates predicts the actual votes well。 The extension combines the best of the PMV and the adaptive model. It acknowledges the importance of expectations already accounted for by the adaptive model, while maintaining the PMV model's classi

44、cal thermal parameters that have direct impact on the human heat balance。 It should also be noted that the new PMV extension predicts a higher upper temperature limit when the expectancy factor is low. People with low expectations are ready to accept a warmer indoor environment. This agrees well wit

45、h the observations behind the adaptive model。Further analysis would be useful to refine the extension of the PMV model， and additional studies in non-airconditioned buildings in warm climates in different parts of the world would be useful to further clarify expectation and acceptability among occup

46、ants。 It would also be useful to study the impact of warm office environments on work pace and metabolic rate。ConclusionsThe PMV model has been validated in the field in buildings with HVAC systems， situated in cold， temperate and warm climates and studied during both summer and winter. In nonaircon

47、ditioned buildings in warm climates, occupants may perceive the warmth as being less severe than the PMV predicts， due to low expectations。An extension of the PMV model that includes an expectancy factor is proposed for use in nonairconditioned buildings in warm climates。The extended PMV model agree

48、s well with field studies in non-airconditioned buildings in warm climates of three continents。Thermal comfort and air quality in a building should be considered simultaneously. A high perceived air quality requires moderate air temperature and humidity。AcknowledgementFinancial support for this stud

49、y from the Danish Technical research Council is gratefully acknowledged。ReferencesAndersson, L。O。, Frisk， P。， Löfstedt, B。， Wyon， D。P。， （1975）， Human responses to dry, humidified and intermittently humidified air in large office buildings. Swedish Building Research Document Series， D11/75。ASHRA

50、E 551992: Thermal environmental conditions for human occupancy。 American Society of Heating， Refrigerating and Air-conditioning Engineers, Inc。Baker， N。 and Standeven， M. （1995）, A Behavioural Approach to Thermal Comfort Assessment in Naturally Ventilated Buildings。 Proceedings from CIBSE National C

51、onference， pp 7684.Brager G。S.， de Dear R。J。 （1998）， Thermal adaptation in the built environment： a literature review. Energy and Buildings, 27, pp 8396。Cena， K。M. （1998）, Field study of occupant comfort and office thermal environments in a hotarid climate。 （Eds。 Cena， K。 and de Dear, R。）. Final rep

52、ort, ASHRAE 921RP, ASHRAE Inc., Atlanta。de Dear， R., Fountain, M.， Popovic, S。, Watkins, S。, Brager， G。， Arens， E.， Benton， C。， (1993a)， A field study of occupant comfort and office thermal environments in a hot humid climate。 Final report， ASHRAE 702 RP， ASHRAE Inc.， Atlanta。de Dear， R。， Ring， J。W。

53、, Fanger, P.O。 （1993b)， Thermal sensations resulting from sudden ambient temperature changes。 Indoor Air， 3, pp 181-192。de Dear， R。 J。, Leow， K。 G。 and Foo， S。C。 （1991）， Thermal comfort in the humid tropics： Field experiments in air-conditioned and naturally ventilated buildings in Singapore。 Intern

54、ational Journal of Biometeorology， vol。 34， pp 259265。de Dear, R。J。 (1998）, A global database of thermal comfort field experiments. ASHRAE Transactions， 104（1b）， pp 11411152.de Dear， R。J. and Auliciems, A. (1985)， Validation of the Predicted Mean Vote model of thermal comfort in six Australian field

55、 studies。 ASHRAE Transactions， 91（2）, pp 452- 468.de Dear, R。J.， Brager G。S。 (1998)， Developing an adaptive model of thermal comfort and preference。 ASHRAE Transactions， 104（1a)， pp 145-167。de Dear， R。J。, Leow， K.G。， and Ameen， A。 (1991）， Thermal comfort in the humid tropics - Part I: Climate chambe

56、r experiments on temperature preferences in Singapore. ASHRAE Transactions 97(1)， pp 874879.Donini， G.， Molina， J。， Martello, C.， Ho Ching Lai, D。, Ho Lai， K。， Yu Chang， C.， La Flamme， M.， Nguyen, V.H。, Haghihat， F。 （1996）, Field study of occupant comfort and office thermal environments in a cold cl

57、imate。 Final report， ASHRAE 821 RP， ASHRAE Inc。， Atlanta。Fang, L。， Clausen， G., Fanger， P。O。 （1999）, Impact of temperature and humidity on chemical and sensory emissions from building materials。 Indoor Air， 9， pp 193-201.Fanger, P.O. (1970), Thermal comfort. Danish Technical Press， Copenhagen, Denma

58、rk.Fouintain, M.E。 and Huizenga， C。 （1997）, A thermal sensation prediction tool for use by the profession。 ASHRAE Transactions， 103（2), pp 130136。Humphreys， M.A。 （1978)， Outdoor temperatures and comfort indoors. Building Research and Practice， 6（2）, pp 92-105.Krogstad, A。L。， Swanbeck, G。， Barregård， L。， et al. （1991）， Besvär vid kontorsarbete med olika temperaturer i arbetslokalen - en prospektiv undersökning (A prospective study of indoor climate problems at different temperatures in offices）， Volvo